Twisted bones in unity but not in blender
Try applying your transforms before you export. Select the object then at the top of the viewport click Object button-&gt;Apply-&gt;All Transforms. Then export it. This solves a lot of Blender to Unity issues and is something you should normally do with exports.
If not that it also might be an armature pose issue between editing modes (Object mode of armature, edit mode, pose mode etc not set properly)